The cornerstone for managing this condition
remains the management of the underlying cause
(e.g., sepsis). Further management may not be
necessary in patients with mild abnormalities in
coagulation and no evidence of bleeding. Guidelines
for management are based mainly on expert
opinion, which suggests replacement of
coagulation proteins and platelets in patients
who are bleeding. Platelet transfusion is indicated
to maintain a platelet level of more than
50,000 per cubic millimeter, along with the administration
of fresh-frozen plasma to maintain a prothrombin
time and activated partial-thromboplastin
time of less than 1.5 times the normal control
time and a source of fibrinogen to maintain a fibrinogen
level of more than 1.5 g per liter.28
The use of antifibrinolytic agents is contraindicated
in the management of disseminated intravascular
coagulation, since the fibrinolytic system
is required in recovery to ensure the dissolution
of the widespread fibrin. Some guidelines recommend
the administration of therapeutic doses of
unfractionated heparin in patients with a thrombotic
phenotype (e.g., gangrene),28 but such recommendations
remain controversial because of
the difficulties in monitoring treatment in a patient
who already has a prolonged activated partialthromboplastin
time; in addition, heparin administration
may provoke hemorrhage. Currently, there
is insufficient clinical evidence to make a firm
recommendation on the use of heparin in patients
with disseminated intravascular coagulation.
Pathophysiological Mechanisms
Thrombocytopenia may arise because of decreased
production or increased destruction (immune
or nonimmune) of platelets, as well as from
sequestration in the spleen. Among patients who
are admitted to an ICU, the condition occurs in
about 20% of medical patients and a third of surgical
patients. The cause of this condition is often
multifactorial. Patients with thrombocytopenia
tend to be sicker, with higher illness-severity
scores, than those who are admitted with normal
platelet counts.29 Table 3 lists the differential diagnoses
of thrombocytopenia in the critical care
setting. Given the long list, it is important to identify
patients in whom thrombocytopenia requires
specific and urgent action (e.g., heparin-induced
thrombocytopenia and thrombotic thrombocyte
pathophysiological